With the global warming and sea level rising, it is widely recognized that there is an increasing tendency of typhoon occurrence frequency and intensity. The defenses code against typhoon attacks for nuclear power pla...With the global warming and sea level rising, it is widely recognized that there is an increasing tendency of typhoon occurrence frequency and intensity. The defenses code against typhoon attacks for nuclear power plant should be calibrated because of the increasing threat of typhoon disaster and severe consequences. This paper discusses the probabilistic approach of definitions about ＂probable maximum typhoon＂ and ＂probable maximum storm surge＂ in nuclear safety regulations of China and has made some design code calibrations by use of a newly proposed Double Layer Nested Mtdti-objective Probability Model （DLNMPM）.展开更多
It is common to assume that structures are designed in view of 50 year life cycle as per Euro-Code 2 and other codes. In special cases, structures are designed in view of longer life cycle, such as bridges, important ...It is common to assume that structures are designed in view of 50 year life cycle as per Euro-Code 2 and other codes. In special cases, structures are designed in view of longer life cycle, such as bridges, important infrastructure facilities, important religious structures or in case of extended returning period of seismic event or floods. Beside issues of durability and maintenance aspects, this involves also the need to cover the probability of exceeding characteristic design live loads during the extended period, while keeping the same levels of the accepted risk that were assumed by the various codes, as good enough for the standard 50 year life cycle. Bearing in mind that design procedures, formulations, materials characteristic strengths and partial safety factors are used for these structures as per the existing codes, scaling of partial safety factors, or alternatively an additional ＂compensating＂ factor is required. A simplified approach and procedure to arrive at a reasonable calibration of the code safety factors based on 50 years to compensate for an extended life cycle, based upon structural reliability considerations, is proposed.展开更多
This paper proposes a digital background calibration algorithm to correct linearity errors in a pipelined analog-to-digital converter（ADC）.The algorithm does not modify the analog circuit of pipelined stages and cal...This paper proposes a digital background calibration algorithm to correct linearity errors in a pipelined analog-to-digital converter（ADC）.The algorithm does not modify the analog circuit of pipelined stages and calibrates the raw conversion output by using a backend digital logic.Based on the analysis of the output codes,the calibration logic estimates the bit weight of each stage and corrects the outputs.An experimental 14-bit pipelined ADC is fabricated to verify the algorithm.The results show that INL errors drop from 20 LSB to 1.7 LSB,DNL errors drop from 2 LSB to 0.4 LSB,SNDR grows from 57 to 65.7 dB and THD drops from -58 to -81 dB.The linearity of the pipelined ADC is improved significantly.展开更多
基金supported by the Nationam Natural Science Foundation of China(Grant No.50679076)Office of State Flood Control and Drought Relief Headquarters of China(Grant No.20060120)
文摘With the global warming and sea level rising, it is widely recognized that there is an increasing tendency of typhoon occurrence frequency and intensity. The defenses code against typhoon attacks for nuclear power plant should be calibrated because of the increasing threat of typhoon disaster and severe consequences. This paper discusses the probabilistic approach of definitions about ＂probable maximum typhoon＂ and ＂probable maximum storm surge＂ in nuclear safety regulations of China and has made some design code calibrations by use of a newly proposed Double Layer Nested Mtdti-objective Probability Model （DLNMPM）.
文摘It is common to assume that structures are designed in view of 50 year life cycle as per Euro-Code 2 and other codes. In special cases, structures are designed in view of longer life cycle, such as bridges, important infrastructure facilities, important religious structures or in case of extended returning period of seismic event or floods. Beside issues of durability and maintenance aspects, this involves also the need to cover the probability of exceeding characteristic design live loads during the extended period, while keeping the same levels of the accepted risk that were assumed by the various codes, as good enough for the standard 50 year life cycle. Bearing in mind that design procedures, formulations, materials characteristic strengths and partial safety factors are used for these structures as per the existing codes, scaling of partial safety factors, or alternatively an additional ＂compensating＂ factor is required. A simplified approach and procedure to arrive at a reasonable calibration of the code safety factors based on 50 years to compensate for an extended life cycle, based upon structural reliability considerations, is proposed.
文摘This paper proposes a digital background calibration algorithm to correct linearity errors in a pipelined analog-to-digital converter（ADC）.The algorithm does not modify the analog circuit of pipelined stages and calibrates the raw conversion output by using a backend digital logic.Based on the analysis of the output codes,the calibration logic estimates the bit weight of each stage and corrects the outputs.An experimental 14-bit pipelined ADC is fabricated to verify the algorithm.The results show that INL errors drop from 20 LSB to 1.7 LSB,DNL errors drop from 2 LSB to 0.4 LSB,SNDR grows from 57 to 65.7 dB and THD drops from -58 to -81 dB.The linearity of the pipelined ADC is improved significantly.
